feat: add tk_strings

README.txt

@@ -22,3 +22,26 @@ int main() {
 
 Define DEBUG to initalize memory with OXFE, to detect uninitialized memory.
 Define DEBUG AND TK_MEMORY_TRACK to catch memory leaks when calling tk_check_memory_leaks().
+
+
+*** tk_strings.h ***
+```
+#define TK_STRINGS_IMPLEMENTATION
+#include "tk_strings.h"
+
+#include <stdlib.h>
+
+int main() {
+    char str[] = "  Hello, World  ";
+    tk_str_to_lower(str);
+
+    char* trimmed = tk_str_trim(str);
+    uint8_t contains = tk_str_contains(trimmed, "hello");
+
+    free(trimmed);
+    return contains ? 0 : 1;
+}
+
+```
+
+String utilities include counting characters/substrings, splitting by character or substring, case conversion, concatenation, trimming, and substring checks.